The QR code is simply a URL shortener. It downloads a save file to your smartphone . You then need to transfer that file to a computer, then to a flashcart, then to the DS.
The search term is a grail hunt for a solution that does not exist in the way most players imagine. The Nintendo DS cannot scan QR codes. The 3DS cannot scan them for DS games. And any video claiming otherwise is either using emulators or flat-out lying. pokemon platinum nds qr code work
In the original retail version of Pokémon Platinum, there is no menu option or hardware interaction that utilizes a camera to scan QR codes. During its era, Nintendo used Mystery Gifts The QR code is simply a URL shortener